Testing in CodeIgniter 4: Build with Confidence

🧪 CodeIgniter 4 Testing Guide

Build Confidently with PHPUnit & Feature Tests

Testing is not just a good practice—it's a must for modern web development. CodeIgniter 4 comes with integrated support for PHPUnit and allows developers to write **feature**, **unit**, and **HTTP tests** that ensure application stability and correctness.

🧱 Types of Tests in CI4

• Unit Tests: Test isolated functions, models, or services
• Feature Tests: Simulate real HTTP requests to controllers
• HTTP Tests: Validate routing, response codes, and content

⚙️ Setting Up PHPUnit

composer require --dev phpunit/phpunit
cp phpunit.xml.dist phpunit.xml

Make sure `phpunit.xml` is correctly pointing to your test suite directories like app/Tests.

🧪 Example: Unit Test

namespace App\Tests\Unit;

use CodeIgniter\Test\CIUnitTestCase;
use App\Models\UserModel;

class UserModelTest extends CIUnitTestCase
{
    public function testFindUserByEmail()
    {
        $model = new UserModel();
        $user = $model->where('email', 'test@example.com')->first();

        $this->assertIsArray($user);
        $this->assertEquals('test@example.com', $user['email']);
    }
}

🌐 Example: Feature Test (Controller)

namespace App\Tests\Feature;

use CodeIgniter\Test\FeatureTestTrait;
use CodeIgniter\Test\CIUnitTestCase;

class HomeTest extends CIUnitTestCase
{
    use FeatureTestTrait;

    public function testHomePageLoads()
    {
        $result = $this->call('get', '/');
        $result->assertStatus(200);
        $result->assertSee('Welcome');
    }
}

✅ Best Practices for Testing

• Use FeatureTestTrait for controller tests
• Mock external services to avoid real API calls
• Run tests regularly with CI/CD tools (e.g. GitHub Actions)
• Isolate database with test transactions

🚀 Run All Tests

php vendor/bin/phpunit

#PHPUnit #CodeIgniter4 #Testing #WebDevelopment

🧩 Conclusion

Testing in CodeIgniter 4 is intuitive, flexible, and built right into the framework. By mastering PHPUnit and feature tests, you’ll catch bugs early, ship faster, and maintain cleaner code over time.

✅ Want to Build Bug-Free Apps?

Stay tuned for more tutorials on building modern PHP apps!

Visit Blog

Happy Testing! 🔍